Lung volumes and exercise
Tidal volume is the amount of air breathed in with each normal breath. The average tidal volume is 0.5 litres (500 ml).
Inspiratory reserve volume is the maximum amount of additional air that can be taken into the lungs after a normal breath.
Expiratory reserve volume is the maximum amount of additional air that can be forced out of the lungs after a normal breath.
Residual volume is the amount of air left in the lungs after a maximal out breath. This air helps to keep the lungs partially inflated to protect the microscopic structures from being damaged.
These volumes can be seen in this spirometry trace.
During exercise, tidal volume increases as the depth of breathing increases and the rate of breathing increases too. This has the effect of taking more oxygen into the body and removing more carbon dioxide.
